Display issues with touchkit 4.1.0 and NativeSelect

My application was running fine with Vaadin 7.5.6 and Touchkit 4.0.4.
I upgraded to Vaadin 7.7.3 and Touchkit 4.1.0
It functions okay but I have two display problems I haven’t resolved yet.
The first one is the dropdown boxes aren’t displaying the down chevron. I am using NativeSelect and no custom styles, just whatever comes with Touchkit and Vaadin. I can see there is an inline style setting on it:

.v-filterselect-button::before {
    content: fa-chevron-down;
    font-family: "FontAwesome";
    color: #00a3e8;
    margin-left: 5px;

and I have a warning on fa-chevron-down: ‘Invalid property value’ and the font family ‘FontAwesome’ is overridden with ‘ThemeIcons’, but the font family is likely okay because inspecting the font tells me FontAwesome Regular is loaded and ‘used as’ ThemeIcons. So it looks like the real problem is fa-chevron-down.
I tried changing the style to use “\f078” instead of fa-chevron-down, which is what the non-touchkit applications I have use, but that didn’t make any difference.
The second display problem concerns a more normal button. I have a big blue button with a white caption. The caption has shifted to below the button and (because it is white-on-white) disappears. The problem is caused by v-button-wrap which now has display:block added inline. When I turn that off it comes right. Does it need to have that display:block setting? I can turn it off on mine easily but it looks like maybe a bug.
The chevron issue is, for me, harder to figure out.
edit: I also noticed there is an inline reference to a background image on style v-filterselect-button. The image is referred ro by:

background: transparent url(common/img/sprites.png) no-repeat -5px -8px; and the image is not found by the browser. Turning it off and on makes no difference. I’m not sure where that image is supposed to come from, it is not referenced in my non-touchkit applications.
Thanks for any help

another edit…
I’ve played around with the css a lot since the above. I find I need to modify the following:

margin-right: -1em;
margin-right: 0em; // change to this
height: 1em;
height: 2em;// change to this

.mytheme .v-filterselect [class$="button"]

right: 5px;
width: 20px;// change to this
position: absolute;
position: relative;// change to this
top: 50%;
top: 0%;// change to this

.mytheme .v-filterselect [class*="input"]

width: 108% !important;// change to this (from 100%)

.mytheme .v-filterselect [class$="button"]
margin-left: 5px;
margin-left: 0px;// change to this

That gives me a decent enough result in my browser. I haven’t seen what it looks on a mobile device yet.
But I am wondering if there are any downside implications to changing this css.

I found the solution to this and it was nothing to do with style sheets, or not directly anyway.
In the earlier (7.5.6) version I assumed I would need two widgetsets because I had two UIs, but that wasn’t allowed.
On a whim I thought I would try this again in the new version and added a widgetset to both of my UI classes. And it worked just fine. The select boxes are behving perfectly well now and the big blue button is displaying its caption. All good.
The one odd message I get is about the widgetset version, in this case the mobile one.

The widgetset in use does not seem to be built for the Vaadin
version in use. This might cause strange problems - a
recompile/deploy is strongly recommended.
Vaadin version: 7.7.3
Widgetset version: 7.6.1

This is a little odd because I did just recompile the widgetset with the 7.7.3 maven plugin.
It does seem quite happy though.